LOUISVILLE, Ky. -- A Delta Air Lines spokesman says a flight that made an emergency landing at Louisville International Airport did so after fluid leaked and caused a "smoky odor" in the plane.

Delta spokesman Anthony Black says the flight bound for Atlanta landed Sunday night without incident. The odor, Black says, came from fluid leaking onto an auxiliary power unit and did not affect the plane's main engines.

Black says the 149 passengers going from Minneapolis to Atlanta were put on another plane and arrived more than four hours late, but safely.